Encodes a member of the BEL family of homeodomain proteins. Plants doubly mutant for saw1/saw2 (blh2/blh4) have serrated leaves. BP is expressed in the serrated leaves, therefore saw2 and saw1 may act redundantly to repress BP in leaves.

These data suggest that BLH2/SAW1 and BLH4/SAW2 establish leaf shape by repressing growth in specific subdomains of the leaf at least in part by repressing expression of one or more of the KNOX genes. [PMID: 17873098]